JPS62268920A - Hot air circulating type cooker - Google Patents

Abstract

PURPOSE:To enable foodstuffs to be cooked through uniform heating, by providing a side wall of a heating chamber with a curved surface part which is projected to the exterior of the heating chamber with the axis of a centrifugal fan as a center. CONSTITUTION:When simultaneously cooking a large amount of foodstuffs 18... by an over operation, two shelves 8, 8 with the foodstuffs 18... placed thereon are set respectively on upper and lower shelf rests 7, 7. Next, a door 16 is closed, and a fan motor 12 and upper and lower heaters 5, 6 are energized, whereby air in a heating chamber 2 is sucked into a casing 9 through suction ports 3 by a hot air circulating fan 11, and is blown off from blow-off ports 4, 4 toward the heaters 5, 6. The hot air is passed on the upper side of the upper shelf 8 and the lower side of the lower shelf 8, impinges on the door 16, and is fed between the shelves 8, 8. Thus, the foodstuffs 18... on the shelves 8, 8 are heated by the heat generated by the heaters 5, 6. With a curved surface part 15 being provided, the spacing between the front side of vanes 11a of the fan 11 and a rear wall 2a is reduced, whereby a vortex flow can be prevented from being generated. Air is sucked into the heating chamber 2 with a uniform constant velocity distribution through the split suction ports 3, whereby the shelves 8, 8 can be uniformly heated, and a uniform backing condition can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention] (Industrial Field of Application) The present invention relates to a hot air circulation type cooking device that uses a centrifugal fan to circulate hot air within a heating device for cooking.

(Prior art) In a heating oven circulation type microwave oven (cooking device), a casing is provided on the outer surface of the heating chamber, and a hot air circulation fan made of a centrifugal fan is installed inside the casing to circulate hot air within the heating chamber. It is being done to

Specifically, conventionally, as shown in FIG.
A suction port C is provided in the center of the rear wall of the heating chamber a, and the suction port C
Air outlets d are provided at the upper and lower positions sandwiching the . Then, a casing d is attached to the outer surface of the rear wall of the heating Wa to form a fan chamber e in which the suction port C and the blowout port d communicate with each other, and the fan chamber e is placed opposite the suction port C to circulate hot air. fan f
By the operation of fan motor (driving the hot air circulation fan) Q and heater b, air from inside a is sucked in from the suction port C to the heating point a, and the air is transferred to each air outlet d,
From d to each heater b, hot air is blown out and sent into the heating area a.

By the way, in such a microwave oven, in order to cook a large amount of food at once, a moving support (not shown) is formed on the peripheral wall of the heating chamber a, and this support is used to set two square shelves j in the heating chamber a. It is being established. However,
Unlike heating using a round rotating plate, it is difficult to apply hot air evenly to the food in such a two-tiered dish (because it is difficult to rotate the rectangular Ij).

Therefore, conventionally, as shown in FIG. 6, shelves j are defined so as to be ti between the intake port C and the air outlets d and d of each upper and lower stage, and the intake air from between the two sheets Ij and j is , hot air is circulated by exhausting to the space above the upper shelf j and the space below the lower shelf llj.

However, in a microwave oven using such a centrifugal fan as a hot air circulation fan, as shown in FIG. There is a drawback in that a swirling flow k... is generated on the front side of the blade of the circulation fan f.

(Problems to be Solved by the Invention) The swirling flow k directly causes a loss of circulation performance, and has the problem that food m is baked unevenly due to turbulence of hot air.

The present invention was made in view of these problems, and its purpose is to provide a hot air circulation type cooker that can cook food with even heating.

[Structure of the Invention] (Means and Effects for Solving the Problems) This invention has a curved surface part centered on the axis of the centrifugal fan 11 that is convex on the outside of the heating chamber 2 on one side wall 2a of the heating chamber 2. 15 narrows the space between the suction side of the blades of the centrifugal fan 11 and one side wall 2a, thereby suppressing the generation of swirling flow k.

(Embodiment) The present invention will be described below based on a first embodiment shown in FIGS. 1 to 3. Figure 1 shows a side cross section of a hot air circulation type microwave oven (cooking device), and Figure 2 shows a front cross section of the same, where 1 is a cabinet (main body), 2 is a heating chamber provided in the cabinet 1, and 3 is a heating chamber provided in the cabinet 1. A suction port divided into a plurality of parts, which will be described later, is provided at the top and bottom center of the rear wall 2a of the heating chamber 2, and 4 is a band-shaped outlet provided at the top and bottom of an even space 42a sandwiching the suction port 3; Reference numeral 5 indicates an upper heater provided on the ceiling surface within the heating chamber 2, and 6 indicates a lower heater provided on the bottom surface within the heating chamber 2. Note that the suction port 3 and the air outlet ports 4, 4
Both are composed of a group of punched holes. A pair of shelf supports 7.degree. 7 are provided at the upper and lower portions of the circumferential wall in the width direction within the heating chamber 2, respectively, so that the rectangular shelves 8 can be arranged in two upper and lower stages. The suction port 3 opens between the upper and lower shelf supports 7, 7, and between the upper shelf support 7 and the upper heater 5, and between the lower shelf support 7 and the lower heater 6. The air outlets 4 are open respectively, and i! II8,8
Intake from between, the same <1118.8 from the upper and lower sides,
The structure is such that air can be blown toward the lower heaters 5 and 6.

On the other hand, 9 is a casing attached to the outer surface of the rear wall of the heating chamber 2. By installing this casing 9, the suction port 3 and the blowout port 4 are provided between the rear wall 2a and the casing 9.
4 constitutes a fan chamber 10 in communication with the fan chamber 10. In addition, a hot air circulation fan 11 made of a centrifugal fan is disposed in the fan 10 facing the central part of the suction port 3, so that the air in the heating chamber 2 can be sucked in at a constant suction speed. ing. That is, the intake port 3 has a three-part structure in which only points A and 8 where the suction speed is slow are opened, such as the center of the hot air circulation fan 11 shown in FIG. The blade 11a...
・Prevent air from being sucked into the parts corresponding to (parts with high suction speed). In other words, the structure is such that the hot air in the heating chamber 2 is sucked only from the portion where the suction speed is slow.

The hot air circulation fan 11 is connected to the rotating shaft of a fan motor 12 provided between the casing 9 and the rear wall of the cabinet 1, and is energized to the fan motor 12 and the upper and lower heaters 5 and 6. In addition to driving the hot air circulation fan 11, the upper and lower heaters 5 and 6 generate heat so that hot air can be circulated into the heating chamber 2 through the divided suction port 3 and air outlet 4.4. I have to.

On the other hand, an arcuate curved surface portion 15 is formed at the rear W2a of the heating chamber 2. The curved surface portion 15 has a suction port 3 facing the hot air circulation fan 11 as shown in FIG.
The inner part including the central part 3a of the hot air circulation fan 11
It bulges out in an arc shape toward the rear around the axis of the.

Then, the distance between the curved surface portion 15 and the inner peripheral side of the blades 11a is set to a minimum, and the hot air circulation fan 1
Air is prevented from flowing from the outer circumferential side (blowout part) of 1 to the suction side.

Note that 16 is a door rotatably attached to the front side of the cabinet 1 for opening and closing the opening of the heating chamber 2, and 17 is a waveguide for guiding microwaves into the heating chamber 2. .

Therefore, when using the hot air circulation type microwave oven configured as described above, when cooking Tami's food 18... at the same time, two pieces of food 11!
Set 18.8 to each bark plate 7.7 in the upper and lower rows. Next, after closing the door 16, by operating the operating section (not shown), the fan motor 12. The upper and lower heaters 5 and 6 are energized. As a result, the air in the heating chamber 2 is sucked into the casing 9 through the suction port 3 by the hot air circulation fan 11, and is blown out toward the upper and lower heaters 5 and 6 from each of the air outlets 4.4. In other words, it becomes hot air and is sent into the heating chamber 2. The hot air from these air outlets 4, 4 flows toward the door 16 through the upper part of the upper shelf 8 and the lower part of the lower shelf. Next, hot air is 1R
16 and is sent between 118.8 and again to the suction port 3.
The food 18 on each shelf 8.8 is heated by the circulation of the hot air and the heat from the upper and lower heaters 5, 6.

Although there is a concern that a swirling flow may occur in the hot air circulation fan 11, the curved surface portion 15 narrows the distance between the front side of the blades 11a and the rear wall 2a. However, it can be seen that short circuits can be prevented and the generation of swirling flows can be prevented.

Therefore, loss due to circulation can be eliminated, and the food 18 can be evenly heated.Moreover, with the divided suction port 3, the air in the heating v2 can be heated at an even and constant speed distribution. Since the shelves 8.8 can be heated uniformly by sucking in the heat, the degree of baking can be made uniform.

Note that the present invention is not limited to the embodiment described above, but may be implemented as a second embodiment shown in FIGS. 4 and 5.

In the second embodiment, a curved surface portion 15 is formed on the entire rear wall 2a of the heating chamber 2. In addition, in the second embodiment, the air outlet 4 is divided into an air outlet 20 and an air outlet 21.
4 is used. Specifically, in the air outlet 4.4, one air outlet 20 is provided facing each of the upper and lower heaters 5 and 6, and the other air outlet 21 is provided near the 1st side of the air outlet 20. and the opening area of the air outlet 20 is the same as that of the air outlet 2.
A structure wider than 1 is used. This allows the hot air to heat food efficiently without trapping heat.

Further, although the present invention has been applied to a hot air circulation type cooker in which heaters are provided in the upper and lower portions of the heating chamber, other types of cooking devices, such as those in which the heater is provided in the casing, are applicable.

Furthermore, in addition to this heater, the present invention may be applied to a device in which a heater is provided in the heating chamber, or in a device in which cooking is performed using hot air.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent short circuits in the centrifugal fan and eliminate the occurrence of swirling flow.

As a result, loss of circulation of hot air is prevented, and food can be cooked with even IKJ heat.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of this invention,
Fig. 1 is a side sectional view of a hot air circulation type cooker, Fig. 2 is a front sectional view thereof, Fig. 3 is a diagram showing the suction speed distribution of a centrifugal fan, and Fig. 4 is a second practical example of the present invention. FIG. 5 is a front sectional view thereof, and FIG. 6 is a side sectional view showing a conventional hot air circulation type cooker. 2...Heating chamber, 3...Suction port, 4...Blowout port, 5
゜6...Upper heater, lower heater (heater), 8...
・Shelf, 11...heat lit circulation fan (centrifugal fan),
15...Curved surface part. Applicant's agent Patent attorney Takehiko Suzue Figure 4 Figure 5F! ! J

Claims (1)

[Claims] A hot air circulation system in which a suction port is provided in the center of one side wall of the heating chamber, an air outlet is provided around the suction port, and a centrifugal fan is provided opposite the suction port to circulate hot air within the heating chamber. A hot air circulation type cooking device, characterized in that a curved surface portion centered on the axis of the centrifugal fan and having a convex portion outside the heating chamber is formed on one side wall of the heating chamber.